/**
 * @classDescription 模拟Marquee，无间断滚动内容
 * @author Aken Li(www.kxbd.com)
 * @DOM
 *  	<div id="marquee">
 *  		<ul>
 *   			<li></li>
 *   			<li></li>
 *  		</ul>
 *  	</div>
 * @CSS
 *  	#marquee {overflow:hidden;width:200px;height:50px;}
 * @Usage
 *  	$("#marquee").kxbdMarquee(options);
 * @options
 *		isEqual:true,		//所有滚动的元素长宽是否相等,true,false
 *  	loop:0,				//循环滚动次数，0时无限
 *		direction:"left",	//滚动方向，"left","right","up","down"
 *		scrollAmount:1,		//步长
 *		scrollDelay:20		//时长
 */
(function ($) {
    var methods = {
        init: function (options) {
            var opts = $.extend({}, $.fn.kxbdMarquee.defaults, options);

            return this.each(function () {
                var $marquee = $(this); 			//滚动元素容器
                var _scrollObj = $marquee.get(0); 	//滚动元素容器DOM
                var scrollW = $marquee.width(); 	//滚动元素容器的宽度
                var scrollH = $marquee.height(); 	//滚动元素容器的高度
                var $element = $marquee.children(); //滚动元素
                var $kids = $element.children(); 	//滚动子元素
                var scrollSize = 0; 				//滚动元素尺寸

                //滚动类型，1左右，0上下
                var _type = (opts.direction == "left" || opts.direction == "right") ? 1 : 0;

                //获取滚动元素的尺寸
                $kids.each(function () {
                    scrollSize += $(this)[_type ? "outerWidth" : "outerHeight"]();
                });

                //滚动元素总尺寸小于容器尺寸，不滚动
                if (scrollSize < (_type ? scrollW : scrollH)) { return; };

                //克隆滚动子元素将其插入到滚动元素后，并设定滚动元素宽度
                $element.append($kids.clone()).css(_type ? "width" : "height", scrollSize * 2);

                var numMoved = 0;
                function scrollFunc() {
                    var _dir = (opts.direction == "left" || opts.direction == "right") ? "scrollLeft" : "scrollTop";
                    if (opts.loop > 0) {
                        numMoved += opts.scrollAmount;
                        if (numMoved > scrollSize * opts.loop) {
                            _scrollObj[_dir] = 0;
                            return clearInterval($marquee.data("intervalID"));
                        };
                    };

                    if (opts.direction == "left" || opts.direction == "up") {
                        var newPos = _scrollObj[_dir] + opts.scrollAmount;
                        if (newPos >= scrollSize) {
                            newPos -= scrollSize;
                        }
                        _scrollObj[_dir] = newPos;
                    } else {
                        var newPos = _scrollObj[_dir] - opts.scrollAmount;
                        if (newPos <= 0) {
                            newPos += scrollSize;
                        };
                        _scrollObj[_dir] = newPos;
                    };
                };

                //滚动开始
                $marquee.data("intervalID",setInterval(scrollFunc, opts.scrollDelay));

                //鼠标划过停止滚动
                $marquee.hover(function () {
                    clearInterval($marquee.data("intervalID"));
                }, function () {
                    clearInterval($marquee.data("intervalID"));
                    $marquee.data("intervalID", setInterval(scrollFunc, opts.scrollDelay));
                });
            });
        },
        getintervalId: function () {
            return $(this).data("intervalID");
        }
    };
    $.fn.kxbdMarquee = function (method) {
        if (methods[method]) {
            return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
        } else if (typeof method === 'object' || !method) {
            return methods.init.apply(this, arguments);
        } else {
            $.error('Method ' + method + ' does not exist on jQuery.tooltip');
        }
    };

    $.fn.kxbdMarquee.defaults = {
        isEqual: true, 	//所有滚动的元素长宽是否相等,true,false
        loop: 0, 		//循环滚动次数，0时无限
        direction: "left", //滚动方向，"left","right","up","down"
        scrollAmount: 1, 	//步长
        scrollDelay: 20 	//时长
    };

    $.fn.kxbdMarquee.setDefaults = function (settings) {
        $.extend($.fn.kxbdMarquee.defaults, settings);
    };
})(jQuery);